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authorDimitry Andric <dim@FreeBSD.org>2015-01-07 19:55:37 +0000
committerDimitry Andric <dim@FreeBSD.org>2015-01-07 19:55:37 +0000
commitca9211ecdede9bdedb812b2243a4abdb8dacd1b9 (patch)
tree9b19e801150082c33e9152275829a6ce90614b55 /lib/sanitizer_common/sanitizer_tls_get_addr.cc
parent8ef50bf3d1c287b5013c3168de77a462dfce3495 (diff)
downloadsrc-ca9211ecdede9bdedb812b2243a4abdb8dacd1b9.tar.gz
src-ca9211ecdede9bdedb812b2243a4abdb8dacd1b9.zip
Import compiler-rt trunk r224034.vendor/compiler-rt/compiler-rt-r224034
Notes
Notes: svn path=/vendor/compiler-rt/dist/; revision=276789 svn path=/vendor/compiler-rt/compiler-rt-r224034/; revision=276790; tag=vendor/compiler-rt/compiler-rt-r224034
Diffstat (limited to 'lib/sanitizer_common/sanitizer_tls_get_addr.cc')
-rw-r--r--lib/sanitizer_common/sanitizer_tls_get_addr.cc131
1 files changed, 131 insertions, 0 deletions
diff --git a/lib/sanitizer_common/sanitizer_tls_get_addr.cc b/lib/sanitizer_common/sanitizer_tls_get_addr.cc
new file mode 100644
index 000000000000..6142ce517db5
--- /dev/null
+++ b/lib/sanitizer_common/sanitizer_tls_get_addr.cc
@@ -0,0 +1,131 @@
+//===-- sanitizer_tls_get_addr.cc -----------------------------------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Handle the __tls_get_addr call.
+//
+//===----------------------------------------------------------------------===//
+
+#include "sanitizer_tls_get_addr.h"
+
+#include "sanitizer_flags.h"
+#include "sanitizer_platform_interceptors.h"
+
+namespace __sanitizer {
+#if SANITIZER_INTERCEPT_TLS_GET_ADDR
+
+// The actual parameter that comes to __tls_get_addr
+// is a pointer to a struct with two words in it:
+struct TlsGetAddrParam {
+ uptr dso_id;
+ uptr offset;
+};
+
+// Glibc starting from 2.19 allocates tls using __signal_safe_memalign,
+// which has such header.
+struct Glibc_2_19_tls_header {
+ uptr size;
+ uptr start;
+};
+
+// This must be static TLS
+__attribute__((tls_model("initial-exec")))
+static __thread DTLS dtls;
+
+// Make sure we properly destroy the DTLS objects:
+// this counter should never get too large.
+static atomic_uintptr_t number_of_live_dtls;
+
+static const uptr kDestroyedThread = -1;
+
+static inline void DTLS_Deallocate(DTLS::DTV *dtv, uptr size) {
+ if (!size) return;
+ VPrintf(2, "__tls_get_addr: DTLS_Deallocate %p %zd\n", dtv, size);
+ UnmapOrDie(dtv, size * sizeof(DTLS::DTV));
+ atomic_fetch_sub(&number_of_live_dtls, 1, memory_order_relaxed);
+}
+
+static inline void DTLS_Resize(uptr new_size) {
+ if (dtls.dtv_size >= new_size) return;
+ new_size = RoundUpToPowerOfTwo(new_size);
+ new_size = Max(new_size, 4096UL / sizeof(DTLS::DTV));
+ DTLS::DTV *new_dtv =
+ (DTLS::DTV *)MmapOrDie(new_size * sizeof(DTLS::DTV), "DTLS_Resize");
+ uptr num_live_dtls =
+ atomic_fetch_add(&number_of_live_dtls, 1, memory_order_relaxed);
+ VPrintf(2, "__tls_get_addr: DTLS_Resize %p %zd\n", &dtls, num_live_dtls);
+ CHECK_LT(num_live_dtls, 1 << 20);
+ uptr old_dtv_size = dtls.dtv_size;
+ DTLS::DTV *old_dtv = dtls.dtv;
+ if (old_dtv_size)
+ internal_memcpy(new_dtv, dtls.dtv, dtls.dtv_size * sizeof(DTLS::DTV));
+ dtls.dtv = new_dtv;
+ dtls.dtv_size = new_size;
+ if (old_dtv_size)
+ DTLS_Deallocate(old_dtv, old_dtv_size);
+}
+
+void DTLS_Destroy() {
+ if (!common_flags()->intercept_tls_get_addr) return;
+ VPrintf(2, "__tls_get_addr: DTLS_Destroy %p %zd\n", &dtls, dtls.dtv_size);
+ uptr s = dtls.dtv_size;
+ dtls.dtv_size = kDestroyedThread; // Do this before unmap for AS-safety.
+ DTLS_Deallocate(dtls.dtv, s);
+}
+
+DTLS::DTV *DTLS_on_tls_get_addr(void *arg_void, void *res) {
+ if (!common_flags()->intercept_tls_get_addr) return 0;
+ TlsGetAddrParam *arg = reinterpret_cast<TlsGetAddrParam *>(arg_void);
+ uptr dso_id = arg->dso_id;
+ if (dtls.dtv_size == kDestroyedThread) return 0;
+ DTLS_Resize(dso_id + 1);
+ if (dtls.dtv[dso_id].beg) return 0;
+ uptr tls_size = 0;
+ uptr tls_beg = reinterpret_cast<uptr>(res) - arg->offset;
+ VPrintf(2, "__tls_get_addr: %p {%p,%p} => %p; tls_beg: %p; sp: %p "
+ "num_live_dtls %zd\n",
+ arg, arg->dso_id, arg->offset, res, tls_beg, &tls_beg,
+ atomic_load(&number_of_live_dtls, memory_order_relaxed));
+ if (dtls.last_memalign_ptr == tls_beg) {
+ tls_size = dtls.last_memalign_size;
+ VPrintf(2, "__tls_get_addr: glibc <=2.18 suspected; tls={%p,%p}\n",
+ tls_beg, tls_size);
+ } else if ((tls_beg % 4096) == sizeof(Glibc_2_19_tls_header)) {
+ // We may want to check gnu_get_libc_version().
+ Glibc_2_19_tls_header *header = (Glibc_2_19_tls_header *)tls_beg - 1;
+ tls_size = header->size;
+ tls_beg = header->start;
+ VPrintf(2, "__tls_get_addr: glibc >=2.19 suspected; tls={%p %p}\n",
+ tls_beg, tls_size);
+ } else {
+ VPrintf(2, "__tls_get_addr: Can't guess glibc version\n");
+ // This may happen inside the DTOR of main thread, so just ignore it.
+ tls_size = 0;
+ }
+ dtls.dtv[dso_id].beg = tls_beg;
+ dtls.dtv[dso_id].size = tls_size;
+ return dtls.dtv + dso_id;
+}
+
+void DTLS_on_libc_memalign(void *ptr, uptr size) {
+ if (!common_flags()->intercept_tls_get_addr) return;
+ VPrintf(2, "DTLS_on_libc_memalign: %p %p\n", ptr, size);
+ dtls.last_memalign_ptr = reinterpret_cast<uptr>(ptr);
+ dtls.last_memalign_size = size;
+}
+
+DTLS *DTLS_Get() { return &dtls; }
+
+#else
+void DTLS_on_libc_memalign(void *ptr, uptr size) {}
+DTLS::DTV *DTLS_on_tls_get_addr(void *arg, void *res) { return 0; }
+DTLS *DTLS_Get() { return 0; }
+void DTLS_Destroy() {}
+#endif // SANITIZER_INTERCEPT_TLS_GET_ADDR
+
+} // namespace __sanitizer